Extrasolar planets are being discovered at an incredible rate today. We have yet to discover another planet that can support life as we know it, but that will very likely change soon. Currently, most exoplanets are discovered indirectly by the influence they have on their host stars. Therefore, we only know the temperature and size of an exoplanet as well as we know the temperature and size of the star it orbits. For low-mass stars in the spectral range between K5 and M2, models do not provide the desired accuracy for these parameters. I improve this accuracy for a sample of planet candidates discovered by the Kepler Space Telescope by using a technique that assigns the parameters of nearby and well studied "stellar twins" to the planet hosting stars. I find these stellar twins by comparing the spectra of planet hosting stars to the spectra of similar nearby stars. By assigning the parameters of the nearby stellar twins to the planet hosting stars, I reduce the uncertainties in size and temperature for the planet hosting stars. This will also reduce the uncertainties in the size and temperature of the exoplanets, and thus allow for a better determination of their habitability.

Exoplanets are planets outside our solar system, and the current explosion in exoplanet discoveries is revolutionizing our understanding of the potential for extraterrestrial life. This prolific era of detections has stemmed largely from the unprecedented observing capabilities of NASA's Kepler Space Telescope. The Kepler Spacecraft collects high precision time-series photometric data on a fixed group of approximately 160,000 stars. The data are represented by temporal lightcurves (i.e. brightness vs. time) that can be used to detect transiting exoplanets, the topic of our research. Transits are events where an orbiting planet partially eclipses its host star, casting a small shadow on the telescope. To detect transit signals, we rely on the Quasi-Periodic Automated Transit Search Algorithm (QATS). As an automated tool, QATS provides a crucial means to reduce the Kepler dataset to a manageable size. However, since the algorithm is sensitive to stellar variability, eclipsing binary stars, and systematic artifacts of the spacecraft, additional analysis is required to separate true detections from false positives. Determining the best way to do this is the present focus of our work. Concurrently, we are exploring the potential for QATS not only to determine orbital period, but also to constrain transit depth and duration (properties related to the size of the exoplanet and to the density of the stellar host). While this increases the complexity of the QATS algorithm and the amount of output to manage, it provides greater potential for a fully automated transit search process with results that are more descriptive of the exoplanet systems detected.

Acoustic levitation is a method of levitating matter against the influence of gravity using sound waves.  Small droplets of fluid can, for example, be suspended in standing wave fields produced by high-power ultrasonic transducers at locations where the gradients of the sound field potentials counterbalance the gravitational forces acting on the droplets, creating a simulated microgravity environment.  These environments could be useful in simulating and studying how chemical and biochemical reactions might take place in space.  Our research builds on earlier work by J.Santa Cruz and J. Griffith who successfully achieved acoustic levitation at EdCC in 2011.  Santa Cruz and Griffith were able to experimentally demonstrate rough preliminary agreement with Bjerknes theory for levitation stability points in a planar field approximation, but they also observed stable particle orbits completely beyond explanation by the planar theory.  Here, we compare our experimental findings to the more general Gor’kov theory of levitation to explain both one- and two-dimensional levitation stability subspaces.

Research on galaxy dynamics indicates that visible matter cannot account for all of a galaxy's mass; the prevailing theory is that each galaxy is surrounded by a halo of dark matter. Dark matter can be studied by observing its gravitational influence on luminous matter, a technique known as dynamical tracing. We measure the orbital velocities of dwarf satellite galaxies as dynamical tracers for a central galaxy. Using data from the Sloan Digital Sky Survey (SDSS) DR8 and HyperLeda databases we have identified massive, isolated galaxies as potential targets and selected NGC 2841, a nearby large spiral galaxy. We also used SDSS to identify potential satellite galaxies and prioritize them for observation. Using the DIS spectrograph on the Apache Point Observatory 3.5m telescope, we have performed optical spectrosopy on a number of satellites to determine their line-of-sight velocities. We will use these results and a Jeans equation approximation to infer the mass of NGC 2841, and by comparing this value to the amount of visible mass, we will estimate the mass of its dark matter halo.

The discovery of a new particle, which we suspect is the long-sought-after Higgs boson, has opened a wide range of opportunities to explore new physics at the Large Hadron Collider (LHC). One particularly promising direction is the search for "flavor violation" in Higgs decays, where a Higgs decays to a non-matching pair of particles. We focus particularly on decays into a tau and a mu lepton (both of which are heavier relatives of the electron). At present, indirect data from low-energy experiments allows these Higgs-to-tau-mu decays to make up up to 10% of all Higgs decays, while the current Standard Model of particle physics does not expect them to happen at all. The goal of my research is to develop a method for separating these decays out of the other billions of collisions that happen every second in the ATLAS detector, and analyzing them in such a way to make flavor violating decays stand out against background events (which look similar but have different origins). This will allow us to put much stricter limits on the rate at which these decays occur, and if any do occur we will have made a big step into previously-unexplored physics territory.

The goal of the New Muon (g-2) Experiment at Fermilab is a fourfold precision increase of the measurement of the anomalous magnetic dipole moment of the muon, with the hope of achieving a 5σ deviation from theory. Such a discovery would provide a basis for the exploration of new physics beyond the Standard Model. Many candidates exist for explaining this discrepancy, such as supersymmetry, dark photons, or lepton substructure. My work involves the characterization and analysis of Silicon Photomultipliers (SiPM’s) in support of the development of the (g-2) calorimeters — the central detector systems required to make the measurement. These avalanche photodiode arrays are a significant change from the previously used vacuum photomultiplier tubes (PMT’s). SiPM’s are extremely compact and can be mounted directly inside the magnetic field of the muon storage ring; characteristics such as these them a distinct advantage over PMT’s. A thorough study of pulse resolution, temperature dependence, gain, rate, and other properties is necessary to understand how SiPM’s may be most effectively utilized in the (g-2) experiment. Analyzing pulse resolution and gain involves exciting the SiPM with two laser pulses spaced 2 to 100 nanoseconds apart and determining how closely the pulses can overlap before a significant amount of information contained in the output of the SiPM is lost. Variations in the size and strength of each pulse have also been introduced in the study, such as saturating the SiPM circuit with a blast of laser light and studying how long it takes the device to recover.